Program.cs

using Orleans.Hosting;
using GPSTracker;
using System.Net;

await Host.CreateDefaultBuilder(args)
    .UseOrleans((ctx, siloBuilder) =>
    {
        // In order to support multiple hosts forming a cluster, they must listen on different ports.
        // Use the --InstanceId X option to launch subsequent hosts.
        var instanceId = ctx.Configuration.GetValue<int>("InstanceId");
        siloBuilder.UseLocalhostClustering(
            siloPort: 11111 + instanceId,
            gatewayPort: 30000 + instanceId,
            primarySiloEndpoint: new IPEndPoint(IPAddress.Loopback, 11111));
    })
    .ConfigureWebHostDefaults(webBuilder =>
    {
        webBuilder.UseStartup<Startup>();
        webBuilder.ConfigureKestrel((ctx, kestrelOptions) =>
        {
            // To avoid port conflicts, each Web server must listen on a different port.
            var instanceId = ctx.Configuration.GetValue<int>("InstanceId");
            kestrelOptions.ListenLocalhost(5001 + instanceId);
        });
    })
    .ConfigureServices((ctx, services) =>
    {
        services.AddHostedService<HubListUpdater>();
    })
    .RunConsoleAsync();

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSignalR().AddJsonProtocol();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseStaticFiles();
        app.UseDefaultFiles();
        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapHub<LocationHub>("/locationHub");
        });
    }
}